It is a world away from Buffy The Vampire Slayer, the teen scream hit in which he plays school librarian Rupert Giles, Buffy's mentor. The one thing the two characters have in common is that they both enjoy the company of young women - but in very different ways.

"He just fancies teenage girls," grins Tony, describing Henry Hutton, his character in the Silent Witness two-partner. "I wanted to explore the scenario of when is it all right for an older man to like younger girls and when it becomes too much, when it becomes unacceptable.

"Hutton is not a paedophile, for which there can be no sympathy and no excuse. He is an ex-military type who becomes infatuated by young girls. But then, when a series of girls end up being killed, he becomes the prime suspect."

It is rare for Tony - a versatile actor who once starred as Frank 'n' Furter in camp musical The Rocky Horror Show - to return to the UK for a role these days, as his career in America has taken off since those coffee ads caused such a stir.

He co-starred with Sharon Maughan, the actress wife of Trevor Eve, in the commercials which cast him as her handsome neighbour always running out of coffee.

The 'will they - won't they?' campaign ran for nearly 10 years and sparked a separate series in the States under the US brand name of Taster's Choice.

Success was a double-edged sword for Tony, who found that screen roles dried up in Britain, despite a flourishing stage career.

He says wryly: "I was box office, I could put bums on seats in the theatre - but TV roles just weren't happening.

"I was earning a decent crust off the commercial, so I was able to pick and choose a bit. But if you are not in the public eye and on screen, then your media profile diminishes. That's when I decided to try my lot in the States."

There was no instant success for the 47-year-old, who admits it was his partner Sarah who snapped him out of a downward spiral. "I was sitting over in the States twiddling my thumbs, while she was back in England having to cope with work, our two daughters and the home.

"Frankly, she told me to stop moaning, get off my bottom and do something positive, like taking acting classes.

"I bristled a bit - I had been to drama school," he says in mock outrage. But he signed up with Milton Katzelas whose pupils have included Michelle Pfeiffer and George Clooney.

"His teaching is about attitude to life as well as acting and he is held in huge regard there. When he walks into a class everyone applauds."

It obviously worked as Tony landed a leading role in the sci-fi series VR.5. Sadly it was pulled after only a few episodes, but soon afterwards he was sent the script for Buffy.

"I remember the first time I read it I was sitting in a restaurant and I just started laughing out loud. The other diners must have thought I was mad but I hadn't read anything like it before," he recalls.

"They handed me a contract to sign before the audition, which turned out I'd committed myself to seven years. But the show's great fun to make and it's great to be associated with such a success."

Now Tony spends eight months of the year in California and the rest of it at his country home near Bath with Sarah, an actress and aromatherapist, and their daughters Emily (11) and nine-year-old Daisy.

"I work long hours and I'm away from home for periods of time. But the family comes out to America for a couple of months at a time and when I'm home I can spend a lot of time with them.

"That was what was great about working over here, especially playing a character like Hutton. It's been a great area to explore as an actor because I didn't want him to come across as being evil, pure and simple."